On Monday you may have noticed a video icon at the top right on your screen on Facebook. This free video calling service is competing against the likes of Skype and FaceTime.

With 600 million users on Facebook’s messenger the pressure is heating up against its competitors.

At Facebook’s annual developer conference in March, Chief Executive Mark Zuckerburg said the social network would introduce a myriad of features within Messenger including the ability to create apps that will run in messenger.

Facebook Inc introduced free video calling in its Messenger phone app on Monday as the company seeks to transform its mobile messaging service into a full-featured platform with the same reach as its 1.4 billion user social network.

Messenger, with more than 600 million users, now has a video icon at the top right corner of its screen. Earlier this year, Messenger launched voice and video calling between computers.

Video calling is available on devices using Apple’s iOS and Google’s Android mobile operating systems in Belgium, Canada, Croatia, Denmark, France, Greece, Ireland, Laos, Lithuania, Mexico, Nigeria, Norway, Oman, Poland, Portugal, the United Kingdom, the United States and Uruguay. Facebook said additional regions will be added in the next few months.